[5] At a distance of 45 million light-years (13.7 megaparsecs),[2] it is located relatively nearby, making it a well-studied object.

[6] In Gérard de Vaucouleurs' atlas of galaxy morphological types, NGC 3998 has a classification of SA00(r):, meaning it is unbarred and has an internal ring.

These are supermassive black holes that are surrounded by accretion disks that emit large amounts of energy across the electromagnetic spectrum.

The supermassive black hole has been modeled to be about 8.1+2.0−1.9×108 M☉[2] The AGN's power is relatively low, and like most other low-power radio galaxies, most of its emission is concentrated near its core.

It is thought that the gas disk has just started to align with the stellar distribution, which would also explain the warped shape of the radio emission.